(i) Field of the Invention
The present invention relates to a control device for the operation of a system for treating the surface of a solid running substrate by dielectric-barrier electrical discharge in a controlled gaseous atmosphere.
By way of illustration, the following application examples may be mentioned: the treatment of polymer films for food packaging or the manufacture of capacitors.
(ii) Description of Related Art
Already known in the prior art, for example the document in the name of E. Prinz which appeared in "Plastics Southern Africa" in June 1983, pages 50 et seq., are surface treatment systems of this type which include a treatment device through which the substrate to be treated runs, this device being connected to means for supplying the treatment device with gas, to means for supplying the latter with electrical power in order to produce the electrical discharge and to gas suction means.
Such systems enable substrates to be treated in order to improve their properties, especially those of adhesion, of wettability and of gas or liquid impermeability, thereby enabling their fields of application to be extended.
Thus it has already been proposed, by the document EP-516,804 in the name of the Applicant, to deposit a thin layer of silicon oxide bonded to a substrate made of a polymer material, which comprises subjecting one surface of the substrate to a dielectric-barrier electrical discharge and exposing this surface to an atmosphere containing a silane, by virtue of which a deposition of silicon oxide, bonded to the surface of the substrate, is formed.
The treatment devices for implementing this type of process are generally integrated into a line for the continuous production or conversion of such substrates (for the purpose, for example, of printing, laminating or metallizing them) and these devices are regulated using a pre-established recipe depending especially on the characteristics of the conversion/production into which they are integrated.
However, it will be appreciated that this has a number of drawbacks, especially with regard to the reproducibility of the quality of the substrate resulting from the treatment since it is extremely difficult permanently to adapt the operating parameters of these treatment devices to the operating conditions of such a conversion or production line.